I am currently building a skid-steering rover using a Pixhaw4 Orange Plus and Mission Planner. I am using four BLDC motors and initially planned to use four BLDC motor drivers, but due to synchronization issues, I decided to reduce to to two drivers, each controlling two BLDC motors.
Currently, I have grouped the left motors and assinged them to Throttle Left 73 on Main out 1, and the right motors are grouped and assinged to Throttle Right 74 on Main out 3. The Dir pins of the motor drivers are connected to Aux out 1 for the left motors and Aux out 3 for the right motors to control the direction of motors. I have set the MOT type to ‘brushedWithRelay’
The problem is that the left motors connected to Main out 1 work properly, but the right motors connect to Main out 3 do not operate. I suspected that Main out 3 might be the issue, so I tried connecting to other output pins, but the same problem persisted. I also tried connect the wiring to another spare Pixhawk 4, but the issue remained. And when connect right motors to Main out 1, it work.
I understand that using motor drivers instead of ESCs with Pixhawk is not the typical setup for rovers, but in my case, motor drivers are required. Additionally, when I try to assign Throttle right to a pin other than Main out 3 and connect the PWM line of the motor driver, the motor also does not respond properly and sometimes runs at full power continuously.
Could you please help me understand the possible cause of this issue and suggest any potential solutions? Thank you.